alternative products:Additional isoforms seem to exist,disease:Defects in CD40 are the cause of hyper-IgM immunodeficiency type 3 (HIGM3) [MIM:606843]. HIGM3 is an autosomal recessive disorder which includes an inability of B cells to undergo isotype switching, one of the final differentiation steps in the humoral immune system, an inability to mount an antibody-specific immune response, and a lack of germinal center formation.,function:Receptor for TNFSF5/CD40LG.,online information:CD40 entry,online information:CD40 mutation db,similarity:Contains 4 TNFR-Cys repeats.,subunit:Monomer and homodimer. The variant form found in the bladder carcinoma cell line Hu549 does not form homodimers. Interacts with TRAF1, TRAF2, TRAF3, TRAF5 and TRAF6.,tissue specificity:B-cells and in primary carcinomas.,
[Isoform I]: Cell membrane; Single-pass type I membrane protein.; [Isoform II]: Secreted.
B-cells and in primary carcinomas.